Helping robotic surgeons to operate on beating hearts
Stopping a heart from beating during surgery is a complicated and risky procedure. Robotic technology that predicts the movement of the heart as it beats, thereby enabling surgical tools to move in concert with each beat, could help cut the risks of such surgery by allowing surgeons to operate on a beating heart as if it were stationary.
The researchers from France's Montpellier Laboratory of Informatics, Robotics, and Microelectronics developed a three-dimensional computerized model that not only tracks the motion of the heart's surface as it beats, but also accounts for the movement of a patient's chest wall during breathing. Known as the "thin-plate spline deformable model", this new computerized approach allows the robotic arm to continually adjust to heart and chest movements during surgery.
The new approach relies on a mathematical representation of the heart's surface as it moves in three dimensions during pumping. Previous attempts to use computer modeling to account for heart and breathing motion have relied on 2D imaging combined with other steps, making them to slow to provide instantaneous feedback during an operation. This new 3D imaging predicts the heart movements in a single step, making it faster in real-life surgical environments.
Robotic arms have become essential in many kinds of surgical procedures, including microsurgery and operations that require extremely delicate movements. However, these machines also prevent the surgeons from using their sense of touch and coordination to adjust for rapidly changing environments. This new computer-generated model makes it possible for the surgeon to focus on suturing or cutting without having to adjust for the moving surface.
The researchers believe their work will ultimately have many potential applications including heart surgery, coronary bypasses, and many kinds of brain surgery. In the shorter term though they say the technology will benefit the large number of patients worldwide who go without less invasive procedures that are not “life-or-death” simply because the risk of complications surrounding stopping the heart outweighed the benefits.
The report, “Three-dimensional Motion Tracking for Beating Heart Surgery Using a Thin-plate Spline Deformable Model,” appears in the International Journal of Robotics Research.